Pump



June 17, 1958 c. c. CARLISLE 2,839,004

PUMP

Filed Oct. 29, 1953 4 Sheets-Sheet 1 l o l a' al 0 u w 8 3/8 Il.4 Sw. 323 SLI, zz

Char/S C. CHN/d@I C* C. CARLISLE June 17, 1958 PUMP Filed oet. 29, 195s 4 Sheets-Sheet 2 June 17, 1958 c3. c. CARLISLE 2,839,004

PUMP

Filed 001'.. 29, 1953 4 Sheets-Sheet 3 fr' ,3, /72/7/ /7 M5 June 17, 1958 c. c. CARLISLE PUMP 4 Sheets-Sheet 4 Filed Oct. 29, 1953 4l|lllllllrlllllllmllllllvINVEN TOR. Ch 2r/es 6. C ar//s/e United States This invention relates to a pump of the type disclosed in my co-pending application for patent, Serial No. 260,454, tiled December 7, 1951, now Patent No. 2,697,985, issued December 28, 1954, and wherein the pump includes a reciprocating piston mechanism that is operated by an actuator powered by the uid being pumped and controlled by an automatic trip valve mechanism, responsive to the piston mechanism. y

The principal object of the present invention is to provide for incorporation kof the actuating or power mechanism directly in the pump unit thereby eliminating the piston rod and ,shortening the length of the pump and providing for more rigid and steadier operating parts.

Other objects of the invention are to provide a pump Structure which permits balancing the pressure of the actuating uid on the respective ends of the operating parts, particularly the main and pilot valves and the trip rod actuating mechanism therefor; to provide a combination pump and power piston; to provide a pump structure which results in uniform displacement on both the up and down strokes of the pump mechanism; to provide a simple quick action control of the pilot valve; to provide atent Od for mounting of the trip spring within the pump cylinder;

and to provide the same fluid pressure per square inch on both the up and down strokes of the actuating mechanisms.

In accomplishing these and other objects of the invention as hereinafter pointed out, I have provided improved structure, the preferred form of which is illustrated in the accompanying drawings wherein:

Figs. 1,'1A and 1B are longitudinal sections through the upper, mid, and lower portions of a well pump constructed in accordance with the present invention, the control valve of the upper portion in Fig. 1 being shown in elevation.

Fig. 2 is a section similar to Fig. 1 but showing the control valve and operating mechanism therefor inse'ction.

Fig. 3 is a view similar to Fig. 2 but showing the pilot and control valves in their other positions.

Fig. 4 isv an enlarged fragmentary section of the tripA rod for eifecting movement of the control valve.

Fig. 5 is a view of the lower end of the trip rod par'- ticularly illustrating mounting of the trip spring within the pump piston.

Fig. 6 is a cross section on the line 6 6 of Fig. 4.

Fig. 7 is a cross section through the pump on theA line 7-7 of Fig. 1.

Fig. 8 is a cross section of Fig. 1A.

Fig. 9"is across section on the line 9-9 of Fig. 1B.

Fig. l0 is a cross section on the line 10-10 of Fig. 5.

i Fig. 11 is a perspective view of the trip or toggle vmechanism for' operating the pilot valve of the control valve mechanism.

Fig. 12 is a view similar to Fig. l1 but showing the toggle in its other tripped position.

Referring more in detail to the drawings:

1 designates a pumping apparatus constructed'in aceordance withA the present invention, including a pump 2,839,9@4 iatented June l?, 1958 ICC unit 2 (Figs. 1A and 1B) in which is incorporated a power mechanism 3 (Figs. 1-8) which is under control of a Valve mechanism 4 (Figs, 1, 2, and 3). The pump* ing apparatus is adapted to be located within the lower portion of a well indicated by the casing or tubing S that extends from above ground to a point near the bottom of the well and cooperates with an inner tubing 6 in forming an annular upow passageway or duct 7 for the well lliquid to be lifted.

The lower end ofthe tubing 5 is conected by a collar 8 (Fig: 1B) with a gas anchor 9 that is supported on or suspended above the bottom of the well and is provided with suitable apertures 10 through which well fluid flows from the well into the gas anchor 9 for upow through an inlet tube 11 that depends within the gas anchor from a standing valve cage 12 that is carried by the collar 8. The other end of the tube 11 (not shown) is in open communication with the space in the gas anchor fory admitting the well fluid for upward ow therethrough to the pumping apparatus. The standing valve cage 12 includes a lower part 14 having an annular tapered lower end 15 to removably seat within a taper 16 that is formed within the head portion 17 of the collar 8 for forming a seal between the well and the tubing 5.

The standing valve cage 12 has an internally threaded axial bore 18 into which the upper end of the inlet tube 11 is threaded. The part 15 has a neck 19. The neck 19 cooperates with ythe body portion of the part 14 to provide an annular shoulder 20 having acircular series of spring seats 21 for springs 22 which support an annular valve ring 23.

The standing valve cage also includes an upper part 24 that is internally threaded as at 25 tol connect with external threads 26 on the neck 19 of the lower part of the valve cage. j

Inset within the upper part 24 and clamped to the neck 19 is a valve seating ring 27 for mounting a ball valve 28 contained within ay valve chamber 29 that is provided within the upper portion of the cage part 24. The upper end of the part 24 has an externally threaded periphery 30 that is threaded within the lower end of attube 31 that forms a continuation of the flow tubing 6.

Formed within the part 24 is an internally threaded recessl 24 of larger diameterv than the valve chamber 2 9 to provide a shoulder 32 for seating a guard plate 33 that limits unseating of the valve 28v and which'has` openings 34 therethrough for ow of well uid'into the lower end of a pump cylinder 35. Formed within the part 24 in registry with the valve ring 23 are ducts or channels 36 that connectthe valve chamber 29with the upflow passagaway 7, the ow of fluid being under control ofthe Valve ring 23 which closese the lower end of the duct 36. s

s Also formed within the part 24 intermediate the ducts 36 are ducts 37 that connect the space beow theV valve seating `r-ing "27 with an annular ilow passageway 38 which is provided between the tubing 31 and the pump cylinder 35. The ducts 37 open upwardly through the neck' 30 and provide portsv 39 that are controlled by an annular valve ring 40 which seats directly on the upper end of the neck 30.

TheV pump cylinder 35 has a lower head 41 thatV is screwed within the end of a lower section 42 of the cylinder. The head 41 has a tapered portion 42' that engageswithin a tapered recess 43 in a coupling member 45. The coupling member 45 has a reduced externally threaded portion 46 that is threaded into the recess 24' to retain the guard plate 33 and provide a flow passageway 47 for flow of well lluid to and from the lower end of the pump by way of aregis'tering port 48? within the head 41. The reduced portion 46 cooperates with the larger upper portion thereof to provide an annular projecting shoulder 49 in registry with the valve ring for seating springs 50 that normally retain the valve ring in closing relation with the ducts37.

The lower section 42 of the pump barrel extends upwardly within the tubing 31 and carries a collar 51. The collar 51 has an axial bore 52 for passing the tubular body 53 of a pump piston 54, the body of'the pump piston being slidably sealed within the coupling 51 by a packing ring 55 that is retained in sealing Contact with the body of the piston between the upper end of the tube 42 and an annular shoulder 56 of the bore 52.

The upper portion of the bore 52 passes through a reduced neck 57 of the coupling that engages within the lower end ofl an upper tube 58 of the pump cylinder or barrel. Extending longitudinally of the upper tube 58 of the pump barrel is an outer tube 59 which is of larger inner diameter than the inner diameter of the tube 58 to provide an annular space 6) surrounding the upper portion of the pump barrel. The tube 59 extends upwardly within the tubing 31 and connects the coupling 51 with a head 61 that forms a coupling with an upper section 31 of the tubing 31. (Shown in Fig. 1A.)

The head 61 has an externally threaded portion 64 threaded into the upper end of the tubing 31, a smaller threaded portion 65 which connects the upper end of the tubing 59 and a still smaller threaded portion 66 that connects with the tubing 58. The annular flow passageway 38 previously described connects with the upper end of the pump cylinder through ports 69 that are provided within the head 61 as shown in Fig. 1A.

The lower end of the passageway 60 discharges through ports 67 that are provided in the wall of the tubing 58. The upper end of the passageway 38 connects with a circular series of ports 68 that open through the offset 68 that is provided in the member 61. Flow through the ports 68 is under control of a Valve ring 70 that seats on the oiset or shoulder 68 under pressure of springs 71. The liquid released by the valve ring 70 is discharged into the passageway 7 through radial ports 72. Pressure fluid is supplied to the passageway 60 through ports 73 leading from a passage 74 surrounding a nipple 75. The nipple 75 extends upwardly through the head 61 and has a conical terminal 76 for seating a ring 77 which closes the lower end of a tubing 78. The tubing 78 is of smaller diameter than the inner diameter of the tubing 31' to provide an annular flow passageway 79 therebetween and which connects with the passageway 74.`

The piston 54 has its lower end reciprocable in the chamber 80 formed by the barrel cylinder 35 and the upper end is reciprocable within the chamber 81 formed within the upper tubing 58 of the barrel. chamber 82 is formed between the coupling 51 and a piston-like head 82 which slidably ts within the tube 58. The tubular body of the piston is formed by a tube 83 having its lower end closed by a head 84 and its upper end screwed into an internally threaded recess 85 of the piston head 82. The head 82 has the collar portion 86 that is provided with an opening S7 corresponding in diameter with the outer diameter of a tube 88. The tube 88 sleeves over the upper end of a spring housing 89.

The tube S8 extends upwardly within the upper pump chamber 81 and has its upper end threaded within the tube 75. The spring housing cooperates with the tube 88 so that the pump chamber 81 is of an annular form and has an eifective capacity corresponding with the eifective capacity of the pump chamber 80 whereby the intake displacement of fluid from the respective chambers is substantially equal to assure continuous flow of well fluid to the top of the well as later described.

The spring housing 89 is carried by a lower tube 90 that is threaded into an internally threaded socket 91 of the lower piston head 84. The tube is interconnected with the housing 89 by a threaded connection 104.

A pressure The upper end of the housing 89 terminates in an inwardly extending lateral ange 92 which forms a stop for a spring seat 93, the flange 92 being of the size to provide the seat and form an opening 94 of suitable diameter to pass a collar 95 of a trip rod 96 which is adapted to engage the spring seat 93. The lower end of the rod 96 carries a nut 97 that forms a stop for a spring seat 98 which cooperates with the spring seat 93 in retaining a coil spring 99 therebetween.

It is thus obvious that the rod and spring are housed within the pump cylinder portion of the pumping apparatus so as to provide a compact structure.

The piston element 82 carries a packing 100 which forms a seal with the tube 88. The pressure tluid acts on areas 101 and 101 on the lower piston head 84 and also on the upper end of tube 90 to move the pump piston in a downward direction in discharging well fluid from the lower pump chamber as later described.

In order to increase the eiciency of the pump and avoid tendency for gas being trapped between the standing valve and the piston, the lower head 84 carries a plunger 1.02 that depends from the piston head and into the bore 48 substantially up to the position of the stand ing valve when the piston is in its lowermost position. In order to prevent solid materials carried in the liquid from being in the bottom of the lower pump chamber the lower head 41 of the cylinder has a conical recess 103 that extends from the wall of the barrel downwardly and inwardly to join with the passageway 48, the taper being sufficient so that there is no tendency of solids to lodge thereon. To substantially complete the displacement, the lower piston has a conical portion 104 substantially conforming to the taper of the recess as shown in Fig. 1B. The trip rod extends through a tubular housing 105 (Fig. 4) to provide a cylindrical chamber 106 enclosing a portion of the rod and which is sealed around the rod at the ends thereof ot' the chamber 106 by packings 107 and 108. The chamber 106 is vented through a port 109. The housing 105 depends from the valve control mechanism so that it is retained in xed position for movement of the rod therein and provide means for balancing the high pressure fluid acting upon the upper end thereof, also for the alternating high and lower exhaust pressures upon the lower end thereof, as now to be described.

The lower portion of the trip rod 96 is of solid cross section and carries a head or piston 110 that is slideable in the cylinder chamber 106 to provide a pressure space 111 encircling the solid portion of the rod and also to provide an upper annular space 106. Pressure liquid is admitted to the space 111 through an axial passageway 112 that is provided in the upper section 113 of the trip rod and which extends through the upper packing and entirely through the control mechanism. The upper end of the chamber 106 is vented through a port 109.

The upper end of the section 113 is open to the high pressure liquid supply so that the high pressure liquid passes through the axial passageway 112 and discharges underneath the piston 110 through lateral ports 114 that connect abore 115 of the lower section of the rod with the passageway 112. With this arrangement, the high pressure fluid acting on the upper end of the rod also acts under the piston 110 to counter-balance this pressure, attention being directed to the fact that the effective area on the underside of the piston is large enough to provide a pressure area corresponding to the pressure areas on which the pressure liquid acts in a downward direction on the rod.

The housing 105 is screwed into the lower end of a tubular casing which forms a housing 116 for the control valve mechanism now to be described.

The housing 116 has an outer diameter smaller than the inner diameter of the tube 78 to form an anular ow passageway 117 therebetween for low of pressure huid as later described. The lower end of the housing 116 is closed by a plug 119 that carries the packing' 107 that forms a seal about the portion 113 of the trip rod 96.

The control valve mechanism comprises a main valve assembly which is contained within the valve housing 116 which has its upper end 120 threadedly engaged with the threads on the inner side of the skirt portiony 121 of a head 122, the head 122 being carried by a collar 123 that is secured to the lowerend of the tubing 6. The tubing 78 is similarly connected with the outside of the skirt portion 121 of the head. The interior of the valve housing 116 provides an upper valve chamber 124 which connects with smaller valve chamber 125 in the head 122. The valve housing 116 also has a lower cylinder valve chamber 126 of smaller diameter than the valve chamber 124 to provide an annular shoulder 127 for arresting the valve assembly in one position thereof.

rl`he valve assembly includes a main piston portion 128 which is slideably contained in the valve chamber 124 and connected with a piston portion 129 contained in the valve chamber 125, the piston portions 128` and 129 being interconnected by a reduced portion 130. The main valve assembly also includes a lower piston portion 128 contained within the lower valve chamber 126 as shown in Figs. 2 and 3. i

Extending upwardly from the piston` portion 129 are spaced ears 130 and 131 to which links 132 and 132 are connected.

The main valve has a longitudinal bore 133 that extends downwardly and terminates below the lower .piston portion 128 and within a reduced extension 134 thereof and which operates within the lower end of the chamber 126 to form an annular vertical passageway 135 .that connects with a pilot valve chamber 136 of the `main valve through ports 137. The ports 137 are adapted to be connected with ports 138 leading to channels 139 that extend upwardly through the main valve body to connect the valve chamber 124. The passageway 117 connects at its upper end with the valve chamber 124 through ports 140 that are under control of the piston portion 128 of the main valve while the lower end of the passageway 117 connects with the passageway supplying pressure fluid to the lower head of the pump piston to force the pump piston downward as later described.

The annular flow passageway 79 extends upwardly and connects with channels 141 that have ports 142 opening into the upper valve chamber 125, the ports 142 being under control of the upper piston portion 129. The lower end of the passageway 79 connects with the lower end of the power chamber 82 through ports 67. yThe main valve also has ports 143 located directly below the piston portion 128 which supply pressure fluid to the passageway 117 through ports 140. The upper valve chamber also has ports 144 `that connect through channels 145 with the upiiow passageway 7. The upper end of the pilot valve chamber 133. is supplied withpressure lluid through the annular space around an upper section 146 (Fig. 2), of the trip rod.

The'pilot valveyincludes piston-like valving portions 147 and 14S connected by a reduced sleeve 149. The upper end of the pilot valve is connected by a cage 150 with the tubular rod section 146 that extendsupwardly from the trip rod section 113 and terminates in a head 1st.

Thetrip rod section 113. extends upwardly through a packing 152 that is retained'by a plug 153 closing the lower end of the valve housing. The lower end of the control piston. has a cap` 154 providedwith a conical face 155 which cooperates with a concavity 156 in the plug 119 to facilitate cleaning out of the lower end of the valve chamber incidental to operation of the control valve.

The lower end of the .pilot valve chamber has a similar cavity as indicated at 157. `The links 132'and 132 are pivotally connected with the ears 130 and 131 by pins 158 and 159; The links132 and V132extend upwardly alongside the upper section 146 of the trip rod and are pivotallyconnected near their terminals thereof by toggles 160 andf161 as best shown in Fig. 3, the connections being eiected at the ends of the toggles by,` pins 162 and 163. The links 165 and 166 of the respective toggles are connected-by trunnions 167 and projecting from the respective sides of the head 151. The links terminate in laterally extending arms 168 and 169, the arm 168 having a longitudinal slot 170 to slideably accommodate the arm 169-therein-as shown in Fig. 3. The arms thus slide one relative tothe other upon breaking of the toggles to their upper and lower positions under pressure of a coil spring 171 having its ends 172 and 173 engaging seats 174 and 175-and upturned ears 176 and 177 on the terminal ends 'of the `arms 168 and`169.

Assuming that the pumping apparatus is assembled within a well so that the well fluid flows through the openings 1i) of the gas anchor 9 and upwardly through the inlet tube 11 to thestanding valve and through the standing valve to the lower chamber and through the valve 40 to the upper chamber 81, depending upon the direction of movement of the pump piston 54. A uid under pressure, which may be part of the fluid pumped from the well, is pumped from the top of the well under pressure through the inner tubing 6 to eect actuation of the pump mechanism.

When the pump piston 54 is at the lower end *of its stroke, the ange 94 has engaged the vstop 93 on'the trip rod and holds the spring 99 compressed until the stored action of the spring 99 overcomes the action ofv the spring 171 through thetoggle and links 132 and 132 whereupon the trip rod snaps downwardly into the position shown in the drawings. This movement of the trip rod eiiects downward movement of the pilot valve 149, since the pilot valve is connected with the trip rod by means of ythe cage 150. The pilot valveis then in'the position shown in Fig. 2. In this position ofthe pilot valve, the main control valve is also in the positionl shown in Fig. 2 because the pressure fluid which has been previously trapped in the passageway 13S'has been relieved through the port 137, port 138, channel 139 and port 145, to the upflow channel 7. Pressure Huid is then being admitted through the tubing 6, port 142, channel 141, passageway 79, passageway 74, channel 73, passageway 3S, and through port 67 `into the annular space S2 where the pressure acts on the piston head 82 to effect raising of the pump piston so that well fluid is drawn through the standing valve seat 27, passageway 47, and passageway 43, into the lower pump chamberS.

It is to be understood that well'uid has previously been admitted through the channel 37, valve ring 4t), passageway 33 through the port 69 into the upper pump chamber 81. rl`herefore, on the upstroke of the piston, the piston head 5,12 displaces the well liuid from the chambcr S1 through the ports 69, channels 68, lifting the valve ring 76 and discharging through the port 72 and into the uplow passageway 7, it being understood that the valve ring 46 is closed under the pressure of the pump piston to prevent backiiow into the well and insure upiiow through the passageway 7.

The pump piston continues to move on the up-stroke until the stop 97 on the trip rod 96 engages the spring seat 98 and compresses the spring 99 to the point where it again overbalances the spring 171. The spring` 99 is then effective to lift the trip rod and break the toggle in an upward direction to lift the pilot valve so thatthe port 137 is incommunication with the space 157. Liquid under pressure then llows through the cage 15@ of the pilot valve and into the space 157 from 'where it ows through the port 137 and through the passageway 13S to act on the lower end face 15S of the control valve and also upon the under side of the piston portion 12S to raise the control valve in its housing. This brings the port 143 into the chamber 124 and'the piston portion 128 above the port 140.

Fluid under pressure then passes through the control -valve passageway 133, port 143, chamber 124, port 140,

Vinto the chamber 80, the liquid being displaced through vthe passageways 48, 47, channel 36 to unseat the valve ring 23 so that it is forced upwardly through the passageway 7 to the top of the well along with fluid that was previously displaced from the upper chamber S1. The pump piston thus continues to reciprocate under control of the valve mechanism to eiect a continuous flow of well tiuid to the top of the well.

On the upstroke, the pressure uid within the combined pump and power piston is exhausted from the upper end of the tube 88, passageway 117, port 140 and ports 144 and channels 145 into the uplow passageway 7, the main control valve being in the position shown in Fig. l.

On the downstroke, the pressure uid is exhausted from the chamber 82 through the port 67, passageway 60, port 73, passageways 74 and 79, channels 141, ports 142 and 144, and channels 145 into the upflow passageway 7, the main control valve being in the position shown in Fig. 3.

Attention is again directed to the fact that the capacity of the lower pump chamber 80, is substantially equal to the capacity of the upper pump chamber 81 and that the pressure per square inch acting upon the respective power areas of the pump piston of equivalent areas are equal thereby assuring that the upiiow is uniform and continuous.

Attention is also directed to the balancing of the trip rod by means of the pressure iiuid. This is eected by admitting pressure fluid to act on the trip rod piston 110 so that a lifting pressure is applied within the chamber 111 for counteracting the pressure acting upon the upper cross-sectional areas of the trip rod, it also being understood that the elective area of the trip rod piston 110 corresponds with the cross-sectional area of the trip rod. The pressure also acts upon the annular upper end of the piston 110 to balance the action of the pressure iiuid of the lowermost end of the trip rod as it alternates between high and lower exhaust pressure into chambers into which housing 10S extends, being equalized through port 109.

The main slide valves various cross-sectional areas are properly proportioned so that the pressure thrusts by the iiuid diter or fluctuate in equal amounts for the upward and downward reciprocating movements depending upon the position of the pilot valve. The pilot valve has a constant equally balanced pressure thrust acting thereon so as to provide uniform action thereof under operation of the trip mechanism.

In analyzing the pressures, it will be seen that there is always high uid pressure thrusting downwardly against the cross sectional area of the piston portion 129 and upwardly against the annular area of the piston portion 128, which exceeds the cross sectional area of the piston portion 128, and there is always low or exhaust pressure acting within the chamber 124 in opposite directions against the annular areas of the piston portion 129 andthe piston portion 128 (which exceed the cross sectional area of the reduced portion 130), While the high and low pressure alternate in intensity (between high and low iiuid pressures) within the chamber 157, the combined downwards thrusts on the various sections exceed the combined upward thrusts against the various sections by the same amount that the combined upward thrusts against the various sections exceed the total downward thrusts when low and high pressure liuids alternate in chamber 157. Therefore, it is evident that as the ever balanced pilot valve is reciprocating between its uppermost and lowermost positions, the tiuid pressure within the chamber 157 alternates between high and low .pressures thereby causing the main slide valve to correspondingly reciprocate in its housing with positively great differential pressures.

From the foregoing, it is obvious that I have provided a pumping apparatus wherein the power mechanism is incorporated directly into the pump structure thereby eliminating the necessity of piston rods. This also results in a more compact and shorter pump mechanism. It is also obvious that the trip rod spring is located within the pump piston structure which further shortens the overall length of the pump.

It is further obvious that the trip rod is completely balanced in such a manner that the spring power is only required to lift the rod and etect movement of the pilot valve. Therefore, the pilot and control valves have extremely quick action to assure positive and continuous operation of the pump.

What I claim and desire to secure by Letters Patent is:

1. A double acting pump including a pump cylinder, means dividing the pump cylinder into separate pump chambers at opposite ends thereof, a combination power and pump piston having reciprocatory movement in the pump cylinder, and having a head reciprocatable in one of the pump chambers and cooperating with said dividing means to provide a power chamber intermediate the pump chambers and between said head and said dividing means, means for admitting pressure uid to the power `chamber to act on said head to effect movement of the combination power and pump piston in one direction, said combination power and pump piston being tubular and having an open end at said head and closed at the other, said dividing means including an axial tube in one end of the pump cylinder and extending into the open end of said piston and cooperating with the wall of the pump cylinder in giving the pump chamber at that end an annular cross-section of substantially the same area as the cross-sectional area of the pump chamber at the other end of the cylinder and provide a power chamber within said pump piston, and means for admitting a pressure iluid through said axial tube into the last named power chamber to act upon said closed end to move said combination power and pump piston in the opposite direction.

2. A double acting pump including a pump cylinder, means dividing the pump cylinder into separate pump chambers at opposite ends thereof, a combination power and pump piston having reciprocatory movement in the pump cylinder, and having a head reciprocatable in one of the pump chambers and cooperating with said dividing means to provide a power chamber between said head and said dividing means, means for admitting pressure uid to the power chamber to act on said head to etect movement of the combination power and pump piston in one direction, said combination power and pump piston being tubular and having an open end at said head and closed at the other, said dividing means including an axial tube in one end of the pump cylinder and extending into the open end of said piston and cooperating with the wall of the pump cylinder in giving the pump chamber at that end an annular cross-section of substantially the same area as the cross-sectional area of the pump chamber at the other end of the cylinder and provide a power chamber within said pump piston, means for admitting a pressure fluid through said tube into the last named chamber to act on said closed end to move the pump piston in the opposite direction, a control valve having connection with said pressure admitting means for controlling admission and discharge of the power uid'to said power chambers, a pilot valve for controlling ow of pressure uid to actuate the control valve, a spring controlled toggle mechanism connecting the control and piston valves, a trip rod extending through said tube and connected with said toggle and having spaced stops, and a spring within the said last named chamber and having ends adapted to be respectively engaged by said stops to reciprocate the trip 9 rod'rfortripping said spring controlled toggle'to'shiftthe pilot valve for effecting movementof thevcontrol valve.

3. A doubleacting pump including a pump cylinder, means dividing the pump cylinder into separate pump chambers at opposite ends thereof, a combination'power and pump piston having reciprocatory movement in the pump cylinder, and having a head reciprocatable in one ofthe pump chambers and cooperating with said dividing means to provide a power chamber, means for admitting pressure uid to the power chamber to act on saidhead toeiect movement of the combination power and pump pistonin one direction, said piston being tubular and having an open end at said head and closed at the other, said dividing means including an axial tube in one end of the cylinder and extending into the open end offsaid piston and cooperating with thewall` of the pump cylint der in giving the pump chamber at that end an annular cross-section of substantially the same area. as, the crosssectional area of the pump chamber at the other end, of the cylinder and provide a power chamber within said pump piston, means for admitting apressure fluid through said tube into the last named chamber to movexthe pump piston in theV opposite direction, la control valve having connection with said pressure admittingmeansvfor controlling admission and discharge of the power fluid to said power chambers, a pilot valve forcontrolling` flow of pressure fluid to actuateV the control valve, a tripirod extendingy through said tube and having spaced stops for.

engaging parts carried by the pump piston to reciprocate the trip rod, said trip rod being normally subjected to the pressure iluid in one direction of its movement, and means for subjectingtthe trip rodvto the action of the pressure fluidin the opposite direction to balance the trip rod. l

4. Aldouble acting pump includinga pump cylinder, means dividing the pump cylinder into separate pump chambers at opposite `ends thereof, a combination power and. pump piston havingreciprocatory movement inthe pump cylinder, and having a head lreciprocatable in one of the pump chambers and cooperating with said dividing means toprovide apower chamber, means for admitting pressure fluid to the power chamber to act on said headto effectmovement of the combination power and pump. piston in one direction, said piston being tubul-ar and having an open end at said head and closed` at the other, said dividing means including an axial tube in one end of the cylinder and extending into the open end of said piston and cooperating with the wall of the pump cylinder in giving the pump chamber at that end an annular cross-section of substantiallyl the same area as the cross sectional area of the pump chamber at the lotherend of the cylinder andprovide` a power chamber within said pump piston, means forfadmitting a pressure fluid through said tube torrnove the pump piston inV the opposite direction, ak control valve having connection .with said pressureV admittingmeans for controlling admission and discharge of the power iluid to said power chambers, a pilot valve for controlling iiow of pressure fiuid to actuate the control valve, a spring housing fixed to the closed end of the piston and extending into the axial tube, a spring in said housing, spring seats for opposite ends of the spring, a trip rod extending through said tube into the spring housing, a snap action toggle connecting the pilot valve with the trip rod, and stops on the trip rod and alternately engageable with said seats, to effect compression of the spring in oppositori to resistance in operation of the toggle for providing the power to trip said toggle in giving a snap action of the pilot valve.

5. A double acting pump including a pump cylinder, means dividing the pump cylinder into separate pump chambers at opposite ends thereof, a combination power and pump piston having reciprocatory movement in the pump cylinder, and having a head reciprocatable in one of the pump chambers and cooperating with said dividing means to provide a power chamber, means for ad- 10 mittingspressureauid to the power chambertoact` on saidfheadto: etfectmovement of the combination, power andl'pump piston in one direction, said piston being tubular-and having an open end at said head and closedv at the other," said dividing-means including an axial tube in one end of the cylinder and extending into the open end of said@ piston and cooperating with the wall of the pump cylinder in giving thepump chamber at that end an annular,A cross-sectionvof substantially the same area-as the,X cross-sectional area of the pump chamber at the other end of the cylinder and provide'a power chamber withiny said pumpv piston, means for admitting apressure fluid throughl said tube to move the pump piston in theopposite direction, a control valve having connection with .saidpressure .admitting means for controlling` admission `and discharge of the power fluid to said power chamber, a pilot valve for controlling ow of pressure Huid to actuate the control valve, a spring housing vxed tothe closed end of the piston and extending into the axial tube, a spring in said housing, spring seats for opposite ends of the spring, a trip ,rod extending through said tube into the spring housing, a snap action toggle connecting and the pilot valve with the trip rod, stops on the trip rod and alternately engageable with said seats, to eiect compression of the spring in opposition to resistance in operation of the toggle for providing the power to tn'p said toggle in giving a snap action of the pilot valve, and means for balancing pressure acting on the trip rod.

6; A double acting pump including a pump barrel havingfluid intake and discharge means at the respective ends thereof, means dividing the barrel into upper and lowerchambers, a hollow pump piston reciprocable in the pump barrel and extending through said dividing means, said pump piston being open at one end, a guide tube `having one end xed with respect to an end of the pump barrel and its other end extending through the open end of the pump piston, a head on said open end of the pump piston yand cooperating with the dividing means for providing a powerl chamber, and means for alternately admitting and discharging pressure uid to and from thepower chamber and to and from the hollow of the pump piston by way of said tube for effecting reciprocation of the power piston in the pump barrel.

7. A double acting pump including a pump barrel `having fluid intake and discharge means at the respective ends thereof, means dividing' the cylinder into upper and lower chambers, a hollow pump piston reciprocable in the pump barrel and extending through said dividing means, said pump piston being open at one end and closed at the other, a guide tube having one end fixed with respect to an end of the pump barrel and its other end extending through the open end of the pump piston, a head on said open end of the ypump piston and cooperating with the dividing means for providing a power chamber therebetween, a tube having one end fixed to the pumpy Vpiston, and` extending in` telescoped relation` with the guide tube, a trip rod extending through said tubes and having spaced apart stops thereon, spring seats on the trip rod intermedi-ate the stops, and a spring between said seats, a control valve mechanism having flow connections with said pressure admitting means, a snap acting connection between the control valve and the trip rod, said spring being alternately compressed by said stops to effect actuation of the snap action connection.

8. A double acting pump including, a pump barrel having Huid intake and discharge means `at the respective ends thereof, means dividing the pump barrel into upper and lower chambers, a hollow pump piston reciprocable in the pump barrel through said dividing means, a guide tube having one end fixed with respect to an end of the pump barrel .and its other end extending into one end of the pump piston in telescoping relation with the hollow of the pump piston, a head on said one end of the pump piston and cooperating with the dividing means for providing a power chamber, means for admitting and discharging pressure uid to and from the power chamber vand to and from the hollow of the piston by way of vsaid spring seats, stop means on the spring housing and on the trip rod for effecting compression of the spring responsive to movement of said power piston, and means connecting the rtrip rod with said control valve mechanism including a toggle and a toggle actuating spring operating in opposition to the rst named spring to effect snap 4action of the valve mechanism.

9. A'double Vacting pump including a pump barrel having upper and lower ends provided with fluid inlet and discharge means, means dividing the pump barrel into an upper pump chamber and a lower pump chamber, a piston having reciprocatory movement through said dividing means, said piston beingv hollow to form a power chamber within said piston and having an open end within the upper chamber and a closed end in the lower chamber, a head on the reciprocatory piston and cooper- `ating with the dividing means to provide a power chamber between said head and said dividing means, means for conducting a pressure uid into said last named. power chamber for moving the piston in one direction to discharge uid from the upper pump chamber and to draw uid into the lower pump chamber, a guide tube extending co-axially through the upper pump chamber and into the open end of the piston for supplying pressure Huid into the power chamber within said piston to act on the closed end for moving the said piston in the opposite direction to discharge Huid from the lower chamber and draw iluid into the upper pump chamber, a control valve having ow connections with said pressure uid admitting means and said guide tube for alternately admitting pressure fluid to the respective power chambers, a trip rod extending through the guide tube and into the piston, a spring housed within said piston, spring seats on the trip rod, means carried by the piston for engaging the spring seats -to serve as abutments for the respective ends of Vthe spring, stops on the trip rod for engaging the spring seats on the respective movements of the piston for compressing the spring, a pilot valve, and a spring .actuated toggle connecting the pilot valve with the control -of said piston.

10. A double acting pump for producing a substantially continuous flow of well fluid from a lower portion of a well to above ground, said pump including'a pump barrel having an upper and lower cylindrical portion, the upper cylindrical portion being of larger diameter than the lower cylindrical portion and providing an annular offset therebetween, a tubular piston having upper and lower portions slidable in the upper and lower portions of the pump barrel and cooperating therewith to provide upper and lower pump chambers in said pump barrel, said upperportion of the piston cooperating with said offset for providing a power chamber encircling the piston intermediate said pump chamber, means in the pump barrel and extending into the upper end of the tubular piston to close the upper portion of the piston from the upper pump chamber for providing a power chamber within said piston, a well iluid inlet and discharge means at the respective ends of the pump barrel for controlling admission and discharge of well fluid to and from the pump chambers, and means for supplying pressure fluid alternately to the respective power chambers for reciprocating the piston in said pump barrel.

l1. A double acting pump for producing a substantially continuous ow of well uid from a lower portion of a well to above ground, said pump including an upper cylindrical barrel portion, a lower cylindrical barrel portion of less diameter, means connecting said barrel portions, a tubular piston having a lower portion slidable in the lower barrel portion and cooperating therewith to form a lower pump chamber, and said piston having a head portion slidable within the upper barrel portion and cooperating therewith to provide an upper pump chamber and a power chamber encircling the piston intermediate said pump chambers, a guide tube in the barrel and extending into the upper end of the tubular piston to provide a power chamber within said tubular piston, well uid-inlet and discharge means at the respective ends of the barrel portion for controlling admission and discharge of well fluid to and from the pump chambers, and means for supplying pressure uid alternately to the respective power chambers for reciprocating the piston in said barrel portions.

12. A double acting pump as described in claim 1l wherein said guide tube has an outer diameter relatively to the inner diameter of the upper pump chamber to provide a capacity corresponding to the capacity of the lower pump chamber.

References'Cited in the le of this patent UNITED STATES PATENTS 1,776,416 Cornell Sept. 30, 1930 2,220,334 Holmberg Nov. 5, 1940 2,331,151 Williams et al Oct. 5, 1943 2,497,348 Ecker Feb. 14, 1950 2,624,285 Hall Jan. 6, 1953 2,629,329 Rose et al Feb. 24, 1953 2,642,045 Potts June 16, 1953 

